Posted
by
samzenpus
on Thursday September 30, 2010 @10:42AM
from the rodent-rain dept.

rhettb writes "In a spectacularly creative effort to rid Guam of the brown tree snake, an invasive species which has ravaged local wildlife and angered local residents, the US Department of Agriculture is planning to 'bomb' the island's rainforests with dead frozen mice laced with acetaminophen. While it might not seem difficult to purge an island of snakes, the snake's habit of dwelling high in the rainforest canopy has so far thwarted efforts to rid the island of the pest. Eradicating the snake is a priority because it triggers more than 100 power outages a year at a cost of $1-4 million and has driven at least 6 local bird species to extinction."

I guess all those warnings about how Tylenol can damage your liver are true!

Ha Ha only serious. I can't find many decent references in a quick Google search, because all the links are "lolz teh armey is dropping Tylenol mice", but Acetaminophen is quite toxic to many animals, including house cats [placervillevet.com]. It works as a poison by damaging the liver.

For a healthy human, the liver can metabolize a normal dose of Tylenol just fine... but if you combine alcohol, Tylenol, and a drawerful of other Acetaminophen-containing products (cough syrup with pain reliever, sleep aid with pain reliever, cocaine/speed/etc cut with pain reliever, etc), you've got trouble on your hands.

Also, there's the problem of would-be suicides who try to overdose on Tylenol-3, the prescription high-dose version with Codeine added. They generally don't die -- largely because there's a specific antidote that hospitals have to neutralize the Acetaminophen before it overwhelms the liver. Those who are too late for that intervention don't die either, not right away... they end up on the list for a donor liver, and get to spend their final weeks wishing that they'd either found a better way to get attention, or that they'd invested in a shotgun.

Once the dead snakes are doped on acetaminophen, don't they face the risk of whatever native species might eat them overdosing on acetaminophen

Probably not. The snake will die after its liver wears itself out breaking down the Acetaminophen. All that will be left in the snake is a worn-out liver and non-toxic Acetaminophen metabolites.

Arsenic, by contrast, doesn't "break down". It's an element, so it kills you and remains Arsenic. Other poisons would likely behave similarly. My guess is that Tylenol (I'm tired of typing the long word) was chosen *because* it's less likely to perpetuate in the food chain. In fact, I think it would be just about impossible for it to get beyond two layers -- the liver of whatever eats the snake should take care of the excess with no trouble.

if you drink more 3 drinks a day, the overdose threshold can be as high as 6grams

since contrary to the popular belief, alcohol is actually protective in case of acetaminophen poisoning, since the P450 enzyme favour ethanol to acetaminophen so there is less N-acetyl-p-benzoquinone imine(the bad metabolite of Tylenol that fuck up your liver) produced, you can read more int he Merck manual [merck.com]

It's Guam (average temp 30C). Something the size of a mouse isn't going to stay frozen very long. The mice are attached to streamers so they get caught in the tree tops (where the snakes are) and get moved by air currents. They are testing it now, having already dropped 250 mice.

Acetaminophen metabolism follows first order kinetics and has a half life of 4-6 hours, depending on how healthy your liver is and how efficient your enzymes are. Taking one single 2.5g dose is probably enough to saturate your enzymes to the point that some damage will be done. However taking 4g divided in 4 doses of 1g every 6 hours will never get you over 2g total blood concentration since your body will be eliminating the drug.

Of course there's an entire other argument about chronic acetaminophen use depleting glutathione/methionine stores over time, but that's an even different story.

And then there's the other argument about chronic alcohol use, people who already have low glutathione stores and induced CYP2E1 cytochromes ready to zap that acetaminphen into NAPQI the minute it enters the liver - but why bore you with pharmacology when you can get your own doctorate?

The withdrawal from marijuana is nothing at all compared to the withdrawal from coffee, or even television. What you incorrectly believe was actually entirely made up by racists in the 1920s, and perpetuated by McCarthyists. To say cannabis incurs no withdrawal whatsoever would be more correct than exaggerating the extremely minor, usually unnoticed, symptoms.

Even Federal Judges at the DEA, reviewing the testimony of experts, have deemed that it is relativey [ccguide.org] harmless, [safeaccessnow.org] and ruled it should be legal.

Yeah, this is actually a damn smart way to go about it. The mice are dead, and the poison destroys the target's liver, while being metabolized into an almost harmless compound, so that whatever eventually eats the snake is less likely to be poisoned in turn.

Of course, that does not mean that something isn't going to go wrong, but seriously, where would we be, as a race, if we never took risks? At least it looks someone actually thought about this for a second, as opposed to the NYC opossum debacle.

There is a journal article [unl.edu] which discusses the acetaminophen toxicity in snakes and lizards. Apparently there are two theories - glutathione depletion leading to hepatic necrosis as you mentioned, or methemoglobinemia, which is apparently a condition where normal oxygen-carrying hemoglobin is replaced by methemoglobin, which does not carry oxygen and effectively causes death due to cellular oxgyen deprivation (I wonder if this would explain the findings of clear fluid in the lungs/trachea of the snakes/lizards they tested this on?). I'm not a doctor or a chemist, by the way, just found it interesting.

Habituation to alcohol most likely creates a increased risk of APAP poisoning.

Acute alcohol ingestion reduces APAP toxicity.

Alcohol habituation "primes the pump" so to speak, for conversion of APAP to toxic metabolites by P450 enzymes. But if you give large amounts of alcohol to someone who has excessive amounts of APAP in their bloodstream, that is what is protective, since the alcohol is preferentially taken up by the P450 enzymes.

The lessons to be learned if you don't want APAP poisoning: (1) don't be a heavy drinker and take APAP and (2) if you do ingest a lot of APAP somehow, drink a lot of booze right away to keep it from poisoning your liver.

This is not medical advice, contact a poison control center if you suspect you have any kind of poisoning.

The article addressed your concern...they said they developed specialized delivery systems that would get stuck in the canopies of the trees to prevent the tainted mice from reaching the ground where other species could be affected. I'm sure a few will make their way down, but from the sound of it the snakes have been the dominant species in the tree canopies and should be pretty effectively targeted so long as the delivery system is effective.

I was stationed on Guam too, from '02 through '08. Definitely a beautiful island.

To be fair, it wasn't that the snakes were *permitted*, but rather that the snakes (presumably) stowed away on a ship, and Hawaii only really cracked down after seeing what happened on Guam. While Hawaii has so far escaped the same level of ecological damage, there are still snakes found every year, and it is unknown whether the tree snake has established a colony on one or more of the Hawaiian islands (with the general consensus of "more likely than not"). You can be sure Hawaii will watching the results of this experiment very closely.

The chance of tylenol (the substance inside the frozen mice) destroying the eco-system on Guam is so minuscule, as to be impossible. On the other hand, the damned snakes _are_ destroying the eco-system.

This. There simply aren't any indigenous vertebrates on Guam *to* be affected, and non-indigenous species like the monitor lizard can always be re-introduced should anyone feel it necessary (which I strongly doubt). All native bird species are technically extinct in the wild, existing only in captivity, save the few birds that have been reintroduced on a trial basis. At worst, this program would push back the potential earliest date for full reintroduction, which is a small price to pay for so thoroughly tipping the odds of success of reintroduction.

As for the power outages, they're a bit of a red herring IMO. There are still random outages (or at least there were when I left), but putting snake-guards on the poles eliminated most of the problems, and most of the ongoing outages seemed to be attributable to problems at the plant (*cough* incompetence and indifference *cough*).